Implement File constructor.

LayoutTests/fast/files/blob-slice-test-expected.txt

Index: LayoutTests/fast/files/blob-slice-test-expected.txt
diff --git a/LayoutTests/fast/files/blob-slice-test-expected.txt b/LayoutTests/fast/files/blob-slice-test-expected.txt
index 0f274d3dbd99ae45e2447b311952393dce8d1a75..794c3e8c1e3fc208bf3b9af063e2cf08553d9786 100644
--- a/LayoutTests/fast/files/blob-slice-test-expected.txt
+++ b/LayoutTests/fast/files/blob-slice-test-expected.txt
@@ -1,28 +1,55 @@
-Slicing from 2 to 3: 2
-Slicing from 2 to 12: 23456789
-Slicing from 2 to 2: 
-Slicing from 2 to 1: 
-Slicing from 2 to -12: 
-Slicing from 2 to 2147483647: 23456789
-Slicing from 2 to -2147483648: 
-Slicing from 2 to 9223372036854775000: 23456789
-Slicing from 2 to -9223372036854775000: 
-Slicing from -2 to -1: 8
-Slicing from -2 to -2: 
-Slicing from -2 to -3: 
-Slicing from -2 to -12: 
-Slicing from -2 to 2147483647: 89
-Slicing from -2 to -2147483648: 
-Slicing from -2 to 9223372036854775000: 89
-Slicing from -2 to -9223372036854775000: 
-Slicing from 0: 0123456789
-Slicing from 2: 23456789
-Slicing from -2: 89
-Slicing from 12: 
-Slicing from -12: 0123456789
-Slicing from 2147483647: 
-Slicing from -2147483648: 0123456789
-Slicing from 9223372036854775000: 
-Slicing from -9223372036854775000: 0123456789
-Slicing without parameters: 0123456789
+Blob sliced from 2 to 3: 2.
+File sliced from 2 to 3: 2.
+Blob sliced from 2 to 12: 23456789.
+File sliced from 2 to 12: 23456789.
+Blob sliced from 2 to 2: .
+File sliced from 2 to 2: .
+Blob sliced from 2 to 1: .
+File sliced from 2 to 1: .
+Blob sliced from 2 to -12: .
+File sliced from 2 to -12: .
+Blob sliced from 2 to 2147483647: 23456789.
+File sliced from 2 to 2147483647: 23456789.
+Blob sliced from 2 to -2147483648: .
+File sliced from 2 to -2147483648: .
+Blob sliced from 2 to 9223372036854775000: 23456789.
+File sliced from 2 to 9223372036854775000: 23456789.
+Blob sliced from 2 to -9223372036854775000: .
+File sliced from 2 to -9223372036854775000: .
+Blob sliced from -2 to -1: 8.
+File sliced from -2 to -1: 8.
+Blob sliced from -2 to -2: .
+File sliced from -2 to -2: .
+Blob sliced from -2 to -3: .
+File sliced from -2 to -3: .
+Blob sliced from -2 to -12: .
+File sliced from -2 to -12: .
+Blob sliced from -2 to 2147483647: 89.
+File sliced from -2 to 2147483647: 89.
+Blob sliced from -2 to -2147483648: .
+File sliced from -2 to -2147483648: .
+Blob sliced from -2 to 9223372036854775000: 89.
+File sliced from -2 to 9223372036854775000: 89.
+Blob sliced from -2 to -9223372036854775000: .
+File sliced from -2 to -9223372036854775000: .
+Blob sliced from 0: 0123456789.
+File sliced from 0: 0123456789.
+Blob sliced from 2: 23456789.
+File sliced from 2: 23456789.
+Blob sliced from -2: 89.
+File sliced from -2: 89.
+Blob sliced from 12: .
+File sliced from 12: .
+Blob sliced from -12: 0123456789.
+File sliced from -12: 0123456789.
+Blob sliced from 2147483647: .
+File sliced from 2147483647: .
+Blob sliced from -2147483648: 0123456789.
+File sliced from -2147483648: 0123456789.
+Blob sliced from 9223372036854775000: .
+File sliced from 9223372036854775000: .
+Blob sliced from -9223372036854775000: 0123456789.
+File sliced from -9223372036854775000: 0123456789.
+Blob sliced without parameters: 0123456789.
+File sliced without parameters: 0123456789.